Toden Arakawa Line

The line grew out of the network built by the Ōji Electric Tramway (王子電気軌道), a company that combined electric-power supply with tram and bus operation in Tokyo's northern suburbs. Founded on 19 April 1910, it opened its first tramway segment, between Asukayama and Ōtsuka, on 20 August 1911. A second-stage line followed, and on 1 April 1913 the section from Minowa (today's Minowabashi) to Asukayama-shita (today's Kajiwara) opened, extending the tramway to about 7.3 kilometres; the Asukayama-shita–Sakaechō stretch opened later the same year, on 31 October 1913.

The Ōji company steadily filled in the network over the following two decades. The Ōji–Asukayama link opened on 17 April 1915, and on 12 November 1925 the Ōtsuka-ekimae–Kishibojinmae and Sakaechō–Ōji sections opened, allowing through running across the system. The route toward Waseda was extended in stages — Kishibojinmae to Omokagebashi on 25 December 1928, Omokagebashi to a provisional Waseda terminus on 30 March 1930, and finally to Waseda itself on 17 January 1932. A separate northern branch from Kamiyabashi to Akabane had opened on 15 December 1927.

Wartime control of electricity and transport brought the Ōji Electric Tramway to an end. On 1 February 1942 the company was dissolved: its power business was absorbed by Kantō Electric Distribution, and its tram operations were transferred to the Tokyo City electricity bureau, becoming part of the Tokyo City tram system. With the creation of the Tokyo Metropolis, the network became the Tokyo Metropolitan tram — the Toden — on 1 July 1943. Within the metropolitan system the former Ōji lines were operated as Route 27 (Minowabashi–Akabane) and Route 32 (Arakawa-shakomae–Waseda).

At its peak the Toden network ran some forty routes across central Tokyo. Faced with worsening road congestion in the 1960s, the cost of building the Toei subway, and pressure to cut loss-making public services, the metropolitan government began abolishing Toden lines from 1967. Under the first financial-reconstruction plan, the routes that make up today's Arakawa Line were themselves slated for closure — Route 27 in fiscal 1970 and Route 32 in fiscal 1971.

These routes were spared because roughly nine-tenths of their length ran on dedicated right-of-way rather than in the street, so they caused little traffic disruption and could not easily be replaced by buses on the chronically congested parallel roads; strong support from residents along the line reinforced the case for keeping it. By the time most Toden lines had been abolished, on 12 November 1972, only the Ōji-ekimae–Akabane portion of Route 27 had been cut, as it could be replaced by bus service. Permanent retention of the remaining section was decided in 1974, and on 1 October that year Routes 27 and 32 were merged into a single Minowabashi–Waseda service under the unified name "Arakawa Line."

One-man operation with single cars, the driver handling fares and announcements alone, was introduced from 1 October 1977 and extended to all trains the following April. On the formal register the route had long been recorded as four separate lines — the Mikawashima, Arakawa, Takinogawa and Waseda lines — and these were only consolidated under the single name "Arakawa Line" in the fiscal 1995 edition of the official Railway Directory. In 2017 the Tokyo Metropolitan Bureau of Transportation sought to raise ridership and revitalise the corridor by giving the line a nickname; from eight candidates put to a public vote, "Tokyo Sakura Tram" was announced on 28 April 2017, and station-numbering with the route symbol SA was introduced from late November of that year. The line today carries fewer passengers than at its 1970s peak but remains a well-known survivor of old Tokyo, running past sites such as Asukayama Park and the Arakawa amusement park.

• 191019 April: the Ōji Electric Tramway company is founded.
• 191120 August: the company opens its first tramway segment, Asukayama–Ōtsuka.
• 19131 April: the Minowa (now Minowabashi)–Asukayama-shita (now Kajiwara) section opens, extending the line to about 7.3 km; Asukayama-shita–Sakaechō follows on 31 October.
• 191517 April: the Ōji–Asukayama section opens.
• 192512 November: the Ōtsuka-ekimae–Kishibojinmae and Sakaechō–Ōji sections open, enabling through running across the system.
• 192715 December: the Kamiyabashi–Akabane branch (later part of Route 27) opens.
• 192825 December: the Kishibojinmae–Omokagebashi section opens.
• 193030 March: the Omokagebashi–(provisional) Waseda section opens.
• 193217 January: the line is completed through to Waseda.
• 19421 February: under wartime electricity and transport controls the Ōji Electric Tramway is dissolved and its tram operations pass to the Tokyo City tram system.
• 19431 July: with the creation of the Tokyo Metropolis the network becomes the Tokyo Metropolitan tram (Toden).
• 1967The metropolitan government begins successively abolishing Toden tram lines amid 1960s road congestion and subway-construction costs.
• 197212 November: most Toden lines are abolished; of today's route only the Ōji-ekimae–Akabane portion of Route 27 is cut, as it can be replaced by bus.
• 19741 October: permanent retention having been decided, Routes 27 and 32 are merged into a single Minowabashi–Waseda service and the unified name "Arakawa Line" is established.
• 19771 October: single-car one-man operation begins, extended to all trains from 1 April 1978.
• 201728 April: the line is given the nickname "Tokyo Sakura Tram"; station numbering with route symbol SA follows from late November.